And in new findings that will be published soon — and are enough to turn this working mother’s feet cerulean — scientists have discovered<br />that the key to a successful long-term booby partnership is the equitable sharing of nest duties year after year.<br />Such egalitarian couples, said Dr. Sánchez Macouzet, “have reached the sweet spot of cooperation, compatibility<br />and a willingness to avoid the exploitation of your partner.”<br />Dr. Drummond and his colleagues have also identified another booby mating pattern<br />that seems to work nearly as well as a stable long-term partnership and in some ways contradicts it: the May-December effect.<br />For reasons that remain mysterious, Dr. Drummond said, booby couples in which one bird is young<br />and the other old often have greater breeding success compared with pairs of the same age.<br />“They’re superfascinating animals and such a good research model,” said David J. Anderson of Wake Forest<br />University in Winston-Salem, N. C., who studies both the blue-footed booby and the related Nazca booby.<br />Should the body mass of the elder nestling decline to 80 percent of normal, however, “it<br />will increase the daily pecking of its sibling by 500 percent,” Dr. Drummond said.
